RenderTileEntityStacks uses JAPI's `Function` instead of Java's `Function`

[unilock]

Charset/src/main/java/pl/asie/charset/module/immersion/stacks/RenderTileEntityStacks.java

Line 22 in 2d331d0

import akka.japi.Function;

This doesn't seem intentional? java.util.function.Function should work equivalently.

Someone else even ran into a crash due to it (somehow):

(I tried fixing it myself, but I'm not familiar enough with ForgeGradle 2.3 to figure out how to get all the dependencies to resolve...)